rust konkurs 2

main.rs

use std::collections::HashSet;
use std::io::{self, BufRead};

enum Token {
    Query(i64),
    Insert(i64),
}

impl Token {
    fn parse(s: String) -> Option<Token> {
        match s.split(" ").collect::<Vec<&str>>().as_slice() {
            ["insert", n] => match n.parse() {
                Ok(n) => Some(Token::Insert(n)),
                _ => None,
            },
            ["query", n] => match n.parse() {
                Ok(n) => Some(Token::Query(n)),
                _ => None,
            },
            _ => None,
        }
    }
}

fn solve(tokens: Vec<Token>) {
    let mut set = HashSet::new();
    for t in tokens {
        match t {
            Token::Insert(n) => {
                set.insert(n);
            }
            Token::Query(n) => {
                let answer = set.iter().filter(|e| e.to_owned() < &n).count();
                println!("{}->{}", n, answer);
            }
        }
    }
}

fn main() {
    let stdin = io::stdin();
    let lines: Vec<_> = stdin
        .lock()
        .lines()
        .map(|s| s.unwrap_or("".to_string()))
        .collect();
    let data: Vec<_> = lines
        .into_iter()
        .map(Token::parse)
        .filter(|e| e.is_some())
        .map(|e| e.unwrap())
        .collect();
    solve(data);
}